The present invention relates to a variable displacement vane pump used as a pressure source for various devices.
A Japanese patent document JP 2003-021076A shows a variable displacement vane pump arranged to vary the volumes of pumping chambers by swing motion of a cam ring, and controlled to decrease a discharge quantity when the pump is driven at a high speed. In an inside abutting surface of a rear body, in a region between an inlet port and an outlet port, there is formed a recessed groove for introducing a high pressure, to alleviate a force pushing the cam ring toward the rear body and thereby to restrain internal leakage.